In general, an image forming apparatus such as a laser printer includes an optical scanner for exposing a peripheral surface of a photoconductor drum to light. The optical scanner typically includes a light source (light source unit), optical elements such as a polygon mirror, an fθ lens and a folding mirror, and a scanner housing in which these optical elements and other components are housed.
The recent trend in the design of the image forming apparatus toward miniaturization involves downsizing of the optical scanner. Hence, in the image forming apparatus appearing on the market in recent years, clearances left between each optical element and the wall of the scanner housing, as well as between the wall of the scanner housing and the main body housing of the image forming apparatus, are designed to be very small.
In the image forming apparatus of this design, if a great force is applied from outside, for example, to a sheet output tray formed on the top side of the main body housing, or the like, the wall of the main body housing is deformed and undesirably pressed against the wall of the scanner housing which may in turn become deformed. Deformation of the wall of the scanner housing would possibly cause the optical elements to be shifted from its original position. This would make it difficult to precisely expose the photoconductor drum to light in all likelihood, and resultantly lower the quality of images to be formed.
There is a need to provide an image forming apparatus such that deterioration of the quality of images formed therein can be suppressed.